1. Field of the Invention
The present invention relates to a substrate processing apparatus and method for processing substrates, such as semiconductor wafers by a plurality of processes including a cleaning process and drying process.
2. Description of the Related Art
A semiconductor device fabricating process employs a processing apparatus that cleans substrates, such as semiconductor wafers (hereinafter referred to simply as xe2x80x9cwafersxe2x80x9d) to remove a resist film formed on the wafers for a photolithographic process, and contaminants adhering to the wafers, such as particles organic substances and metallic impurities, from the wafers. Widely known conventional processing apparatuses of this type are of batch processing systems that clean and dry a plurality of wafers in a batch.
Such a processing apparatus is provided with a wafer processing unit, a rinsing unit and a wafer drying unit. The wafer processing unit processes wafers by supplying process gases and steam into a processing chamber. The rinsing unit immerses wafers in pure water contained in a cleaning tank for rinsing (rinsing process). The wafer drying unit dries wafers by supplying isopropyl alcohol (hereinafter abbreviated to xe2x80x9cIPAxe2x80x9d) into a drying chamber. Processed wafers are subjected sequentially to a rinsing process and a drying process.
An ozone-assisted process is carried out for altering resist films formed on wafers by using, for example, ozone gas (O3 gas) and steam into water-soluble films that can be easily removed from the wafers by a subsequent rinsing process. A hydrofluoric acid cleaning process for removing an natural oxide film and contaminants from wafers uses hydrofluoric acid vapor (HF vapor). When carrying out a plurality of wafer processing processes by a single wafer processing apparatus, a wafer processing unit and a rinsing unit are used for each of the plurality of wafer processing processes, and the plurality of wafer processing processes and rinsing processes are carried out alternately.
However, since the conventional wafer processing apparatus is provided with an individual wafer processing unit, an individual rinsing unit and an individual wafer drying unit, the wafer processing apparatus is large. When carrying out a plurality of processes by a plurality of processing units included in a single processing apparatus, the processing apparatus must be provided with a plurality of wafer processing units and a plurality of rinsing units. Consequently, the processing apparatus needs a large floor space for installation. Wafers processed by a process using a mixture of a processing gas and steam are carried to a rinsing unit. While the wafers are being carried to the rinsing unit, the wafers are exposed to the atmosphere, which is undesirably because the exposure of the wafers to the atmosphere the possibility of formation of a natural oxide film on the wafers. If carrying the wafers to the rinsing unit takes a long time, reaction products produced on the wafers by the process using the mixture of the processing gas and steam and deteriorated films formed on the wafers are changed into the different matters when the same are exposed to the atmosphere. Consequently, it is possible that the reaction products and films which are expected to be easily rinsed off the wafers by a subsequent rinsing process are hardened or become insoluble and remain as contaminants on the wafers.
Accordingly, it is an object of the present invention to provide a substrate processing apparatus small in size and capable of preventing exposure of processed substrates to the atmosphere and to provide a substrate processing method in connection with the apparatus.
To achieve the object, according to one aspect of the present invention, there is provided a substrate processing apparatus for processing a substrate by a plurality of processes, comprising: a first processing chamber for containing a substrate; a second processing chamber for containing the substrate, adjoining the first processing chamber and capable of communicating with the first processing chamber; a supporting member for supporting the substrate so as to carry the substrate between the first processing chamber and the second processing chamber; a solvent vapor supply port through which solvent vapor is supplied into the first processing chamber; a processing gas supply port through which a processing gas is supplied into the first processing chamber; a drying gas supply port through which a drying gas is supplied into the first processing chamber; and a processing liquid supply port through which a processing liquid is supplied into the second processing chamber.
First, the substrate is placed in the first processing chamber when processing the substrate by this substrate processing apparatus. A solvent vapor is supplied through the solvent vapor supply port into the first processing chamber and a processing gas is supplied through the processing gas supply port into the first processing chamber to process the substrate. After the substrate has been processed, the supporting member carries the substrate from the first processing chamber into the second processing chamber. Then, a processing liquid is supplied through the processing liquid supply port into the second processing chamber to process the substrate with the processing liquid. Then, the supporting member carries the substrate from the second processing chamber into the first processing chamber. Then, a drying gas is supplied through the drying gas supply port into the first processing chamber to dry the substrate by a drying process.
Since the process using the processing gas and the solvent vapor, the process using the processing liquid and the drying process are carried out in the first and second processing chambers adjoining each other and capable of communicating with each other, the substrate processing apparatus can be formed in a small size. Since the substrate are not taken out of the processing apparatus during all the processes, the exposure of the substrate, which has been processed by the process using the processing gas and the solvent vapor, to the atmosphere can be prevented.
Since the first and second processing chambers adjoin each other, the substrate can be quickly carried from the first processing chamber to the second processing chamber, can be processed with the processing liquid immediately after the process using the processing gas and the solvent vapor, and can be processed with the drying gas immediately after the process using the processing liquid. Accordingly, the formation of the natural oxide film on the substrate, and the change of reaction products formed and altered on the substrate into different matters can be prevented. Then, processes can be properly carried out and the throughput of the processes can be improved.
Possible processing gases to be supplied through the processing gas supply port include gases containing reactive species (radicals, ions), such as ozone gas, chlorine gas fluorine gas and the like.
For example, the solvent vapor supplied through the solvent vapor supply port may be a steam, the processing gas supplied through the processing gas supply port may be an ozone gas, the drying gas supplied through the drying gas supply port may be a gas containing IPA vapor, and the processing liquid supplied through the processing liquid supply port may be a water.
The substrate processing apparatus may process the substrate by an ozone-assisted process that supplies ozone gas through the processing gas supply port into the first processing chamber containing the substrate after supplying steam through the solvent vapor supply port into the first processing chamber, carry the substrate from the first processing chamber into the second processing chamber by the supporting member, process the substrate by a rinsing process by supplying water through the processing liquid supply port into the second processing chamber, carry the substrate from the second processing chamber into the first processing chamber by the supporting member, and dry the substrate by a drying process that supplies a gas containing IPA vapor through the drying gas supply port into the first processing chamber.
In the substrate processing apparatus, an inert gas pipe-line may be connected to the processing gas supply port so as to supply the inert gas from the processing gas supply port into the first processing chamber.
Preferably, in this case, at least one of the solvent vapor, the processing gas and the drying gas is purged from the first processing chamber by the inert gas supplied through the inert gas pipe-line so that an atmosphere in the first processing chamber is displaced. In the substrate processing apparatus, the second processing chamber may be formed below the first processing chamber.
Thus, the process using the processing gas and the solvent vapor, the process using the liquid and the drying process can be carried out by the substrate processing apparatus requiring a floor space for one processing chamber.
Preferably, in this case, an exhaust pipe-line is connected to the first processing chamber so as to exhaust the atmosphere in the first processing chamber.
Preferably, in this case, a flow control valve is provided in the exhaust pipe-line so as to control a flow rate of the atmosphere exhausted through the exhaust pipe-line to regulate a pressure in the first processing chamber.
Preferably, the substrate processing apparatus is provided with a shutter disposed between the first processing chamber and the second processing chamber and capable of being opened and closed.
The diffusion of the atmosphere created in the first processing chamber into the second processing chamber and the flow of the liquid atmosphere created in the second processing chamber into the first processing chamber can be prevented by closing the shutter while processes are carried out in the first processing chamber and second processing chambers.
Preferably, a plurality of processing gas supply pipe-lines through which different processing gases are supplied, respectively, are connected to the processing gas supply port.
Thus, a plurality of kinds of processes can be achieved by individually using the different gases in combination with a solvent vapor.
Preferably, a plurality of processing liquid supply pipe-lines through which different processing liquids are supplied, respectively, are connected to the processing liquid supply port.
Thus, a plurality of kinds of processes can be achieved by individually using the different processing liquids.
Preferably, in this case, the substrate processing apparatus is provided with a plurality of draining pipe-lines to drain different processing liquids, respectively, from the second processing chamber.
According to another aspect of the present invention, there is provided a substrate processing method for processing a substrate, on which a resist film is formed, by a plurality of processes, comprising the steps of: carrying the substrate into a first processing chamber for containing the substrate; altering the resist film on the substrate into a water-soluble film in the first processing chamber; carrying the substrate, on which the resist film is altered, from the first processing chamber into a second processing chamber for containing the substrate; rinsing the substrate with a water in the second processing chamber so that the water-soluble film is removed from the substrate; carrying the rinsed substrate from the second processing chamber into the first processing chamber; and drying the rinsed substrate in the first processing chamber.
The step of altering the resist film may comprise supplying an ozone gas and a water vapor into the first processing chamber.
Preferably, in this case, the step of altering the resist film is carried out in a pressurized atmosphere in the first processing chamber.
Preferably, the first and second processing chambers are isolated by a shutter while the step of altering the resist film and the step of drying the rinsed substrate are carried out.